Re: [stella] The Demo Image Series #5 - PAL & NTSC Compatible

Subject: Re: [stella] The Demo Image Series #5 - PAL & NTSC Compatible
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Wed, 19 Feb 2003 15:26:28 +0100
> All these sample images use P1 difficulty switch to switch between PAL and
> NTSC version.  That's F7/F8 on my Z26.  Note, Z26 (my version, anyway)
> doesn't recalc the palette once it thinks its a PAL game (that is, colours
> are OK when you start, OK when you switch to PAL mode (F8) but aren't OK
> when you go back to NTSC (F7)).  And sometimes it doesn't seem to work
> properly at all - but does the next time its run.  Could be a bug with
> or Z26.  We'll find out once I get a report from hardware owners who test
> these binaries on a Cuttle cart :)

It's not really a bug in z26. Our autodetection system is just
set up for games that are either PAL or NTSC. ;-) We assume
every game to be NTSC. Only when a game does several stable
frames with more than 290 (I think) scanlines during the first
256 frames of emulation, we switch to PAL and stay that way.
So if you hit F8 during the first four seconds, PAL mode still
does get automatically detected.

To set the palette in z26 you can either use the -cN command
line switch, where N can be 0=NTSC, 1=PAL or 2=SECAM, or you
can use the '-' key (right of '8 9 0'). This will also switch
between NTSC -> PAL -> SECAM -> NTSC.

> Could some PAL-capable guys let me know how this sprite system looks on
> TVs?  The refresh rate is lower on that TV standard, so I'd like some
> detailed feedback, if possible.

I think it looks great. I an't find any problems. The flicker
is a bit more noticeable than at 60 Hz, but that isn't much of
a problem, especially with animated images. I guess PAL users
are used to flickering TV pictures. ;-)

But if you fear that 50Hz might be too low, you could always
use a 60Hz display with PAL colours. Usually PAL TVs are able
to handle a 60Hz signal. My multi-standard TV even switches
to NTSC resolution with PAL colours when I play a 262 line
game on my PAL VCS.

Most TVs will show black bars at the top and bottom of the
screen though. But if you aren't planning to use these areas
or to change the aspect ratio of the pictures anyway, that
doesn't make much of a difference.

Ciao, Eckhard Stolberg

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